Electric switch



May 19,1942. w, A, RAY 2,283,340

ELECTRIC .swI'rcH Filed Aug. 5, 1939 Wi/l/am A. Ray

f INVENTQR,

ATTORNEY.

Patented May 1 9, 1942 UNITED STATES PATENT OFFICE 2.28am ELECTRIC swrrcn William a. Bay, Glendale, Calif. Application August 3, 1939, Serial No. 288,092 2 Claims. (01. zoo-s7) My present invention relates to electric switches and has for its main object the provision of switch actuating means which is ineffective to perform its function until a predeter- "mined condition has been established.

Another object of my invention is the provision of switch actuating means which is effective to perform its function only when electromagnetic means, associated with the actuating means, is energized.

Another object is the provision of a safety switch which is automatically-moved to a safe position when electro-magnetic means, associated with the switch, is deenergized, and manually operated resetting means which is ineffective to actuate the switch until energizatlon of the electromagnetic means is restored.

Other objects and advantages of my invention will be found in the description, the drawing and the appended claims.

For complete understanding of the invention, reference may be had to the following detailed description and accompanying drawing, wherein:

Figure 1 is a diagrammatic view of a switch embodying my invention;

Figure 2 is a view taken along the line 2-2 of Fig. 1; and r Figure 3 is a diagrammatic view of a modified form of switch embodying my invention.

Referring first to Figs. 1 and 2 of the drawing, the numeral il indicates the upper portion of a switch housing, and numeral i2 its cor- The operation of the switch shown in Figs. 1 and 2 is as follows:

Assuming first that the thermoelectric generator 21 is unheated, and consequently that no current is being generated by it, when the push-button is depressed and again released, the armature is not'lifted by the unenergized core and consequently the contacts l5 and 23 remain undisturbed. However, if the thermoelectric device is heated and sufllcient current is being generated by it, when the core is manually brought into engagement with the armature the two are magnetically held together, with the result that when the push-button is then released the armature is moved upward, bringing the contacts together to complete the circuit in which they may be connected. The tension of spring I8 is relatively weak with respect to that of spring 2|.

-The contacts remain thus closed until the current through the energizing coil is interrupted,

, when the armature falls, opening the contacts.

responding lower portion, between the flanges of which is secured a diaphragm i3 of flexible material, such as thin metal. Secured to the diaphragm is an armature l6 insulatlngly carrying an electric contact IS. A contractile spring i6 urges the diaphragm downward. Cooper-able with the armature is an electromagnetic device comprising a U-shaped core I! and an energizing coil it. Manual means for moving the electromagnetic device are provided by a pushbutton 49 having a stem 20 attached to the core. A spring 2|, compressed between the housing and the push-button, urges the electromagnet upward, a pin 22 limiting its movement in that direction.

Cooperating with the contact i5 is another contact 23, insulatlngly supported by a flexible arm 24 secured to the housing. A stop member 25 limits downward movement of the arm 2G. The coil i8 is shown connected by flexible leads 28 to a thermoelectric generating device 21. Flexible leads 28 are provided for connecting the contacts I! and 23 in a control circuit.

The electromagnet is not adapted to attract the armature through space, actual engagement of the core and armature being necessary for movement of the latter. The flexibility of the diaphragm permits the armature to readily align its surfacewiththat of the core and so good mechanical and magnetic contact therebetween is made. 1

The device of my present invention, whilenot so limited, has particular utility in a safety control system for gas burners wherein the thermoelectric deviceis arranged to be heated by a pilot burner for a main burner whose fuel supplyis controlled by an electrically operated valve in circuit with the contacts of the switch. In the event of extinguishment of the pilot burner flame, the armature falls and the switch opens the circuit through the valve. The supply of fuel to the main burner is thus interrupted and cannot be reestablished until the pilot burner is relighted and the switch manually reset.

Obviously, other sources of current for energization of the electromagnet may also be employed, suchas, for example, a rectifier supplied with alternating current from the service lines. The energizing current-may be controlled by any suitable means responsive to a condition which a mercury tube switch 33. The electromagnet is similar to that employed in the device shown in Figs. i. and 2 and comprises a core M having a coil 35 and manual means 38 for moving the core into engagement with the armature.

The operation of this modified i'orm oi switch is substantially identical with that of the switch shown in Figs. 1 and 2 and so further description is believed to be unnecessary.

While in both of the specific embodiments of my invention, shown herein by way of example, the switch is normally open, it is obviously within the scope of one skilled in the art to provide a switch according to my invention which is normally closed. Obviously, also, the electromagnet and the armature may be transposed in the device. Also, if desired, the coil may be held stationery and the core arranged to slide therein.

Still further modifications may be made without departing from the splrit'oi' my invention and I intend therefore that my invention be limited only by the scope of the appended claims.

I claim as my invention:

1. In a manually operated electric switch, a

aaeaseo quent movement in an opposite direction to move said armature member with said core member only when the members are magnetically held in engagement with each other by current how in said coil, means biasing said armature membe: to its unmoved position, and switching means actuated by said movement of said armature member.

2. In a manually operated electric switch, a casing, a flexible diaphragm mounted in said casing, an armature member carried by said diaphragm, a reciprocable core member cooperable with said armature member and mounted in said casing, a coil for energizing said core member, manual means extending thru a wall of said casing for moving said core member in one direction into engagement with said armature member,

said manual means being effective by its subsequent movement in an opposite direction to move said armature member with said core member only when the members are magnetically held in engagement with each other by current flow in said coil, means biasing said armature member to its unmoved position, a first contact element carried by said armature member, and a second contact element engageable by said first contact element when said armature is moved against its bias by said core member.

WILLIAM A. RAY. 

